[Haskell-cafe] Vague: Assembly line process

[Martin Drautzburg]

On Tuesday, 15. June 2010 19:43:26 Steve Schafer wrote:
> On Tue, 15 Jun 2010 19:23:35 +0200, you wrote:
> >When I know my supplies I want to know what I can produce. When I know
> > what I want to produce I want to know what supplies I need for that. Both
> > kinds of questions should be answered by a singe Process thingy.
> >
> >I want to be able to chain processes and the whole thing should still act
> > like a Process.
>
> This is a type of constraint network. If you have access to _Structure
> and Interpretation of Computer Programs_, there is a section therein
> devoted to constraint networks. 

Will check this out. I was hoping that something simpler would suffice. I am 
afraid of CSPs.

Today I was playing with a matrix representation. I mean the one you learn in 
school for linear optimization problems. Usually the matrix is written so it 
tells you how much of each supply you need to produce a unit of outputs. 

So when you know the outputs you can compute what you need as a minimum. You 
can invert the matrix and it'll work on the oppsite direction: when you know 
the inputs it'll tell you what you can produce at most.

Then I thought, what if I replace the (*) and (+) operations which are applied 
when I multipy the matrix with a vector (i.e. a vector if inputs or outputs) 
by something more general. So I replaced (+) by function application and my 
matrix was now a matrix of functions. But then I got lost trying to find a 
way to invert such a matrix.

FWIW: while googeling around how to invert a matrix of functions I stumbeled 
across the "Process Specification Language". At least they defined an 
ontology, but there isn't much of computing stuff there. 
http://www.mel.nist.gov/psl/





-- 
Martin